The viscosity of organopolysiloxanes prepared by the condensation and/or equilibration of organosilicon compound(s) having Si-bonded oxygen in the presence of phosphonitrilic chloride(s) often changes during storage when the phosphonitrilic chloride catalysts are not deactivated after the condensation and/or equilibration reaction. A method for stabilizing the viscosity of organopolysiloxanes obtained from the condensation and/or equilibration of organosilicon compounds in the presence of phosphonitrilic chlorides is described in U.S. Pat. No. 3,398,176 to Nitzsche, in which the phosphonitrilic chlorides are reacted with 1 to 1.5 equivalents of tertiary amine per equivalent of chlorine in the phosphonitrilic chloride.
Therefore, it is an object of the present invention to stabilize organopolysiloxanes which are obtained from the condensation and/or equilibration of organosilicon compounds having Si-bonded oxygen, using phosphonitrilic chlorides as the condensation- and/or equilibration-promoting catalysts. Another object of the present invention is to stabilize organopolysiloxanes against viscosity changes which are obtained from the condensation and/or equilibration of organosilicon compounds having Si-bonded oxygen in the presence of phosphonitrilic chlorides or their reaction products using a substance having a low toxicity and which is free of offensive odor. Still another object of the present invention is to provide a method for removing phosphonitrilic chlorides or their reaction products from organopolysiloxanes which are obtained from the condensation and/or equilibration of organosilicon compounds in the presence of phosphonitrilic chlorides. A further object of the present invention is to provide organopolysiloxanes which are obtained from the condensation and/or equilibration of organosilicon compounds in the presence of phosphonitrilic chlorides that are essentially free of phosphorus compounds, their reaction products and deactivation products.